The Calor Lite® weighs 4.52 kg empty. The BP light 5kg cylinder weighs 3.7kg empty for comparison. The existing Calor 6kg cylinder weights 9kg empty and the BP light 10kg cylinder is 5kg. Add the weight of the gas to get the full weight (eg a full 6kg lite would be 10.52kg and a full BP 10kg would be 15kg)

As the cylinders are ALL a different weight - it is impossible to give a specific answer.

However - all is not lost - you can find our EXACTLY how much gas is left in the cylinder..
On the neck of the cylinder it has an aluminium collar.
This is stamped with two weights the empty bottle weight and the full bottle weight so the full bottle is 7.5 kg more than the empty bottle weight!!!

But sorry to confuse they state the bottle weight in Pounds and ounces -- so you need your calculator..

Thanks all - they're not 7.5kgs at all (good thing I never had a Saturday job in a greengrocers....) but are 3.9kgs.

There's a collar on the (spare-ish) one in the garage but no weights on it? (or at least that I can make sense of!!).

Update...

.....and just read Russell's link - the 3.9 refers to the weight of the gas not the cylinder, net or gross - don't laugh, I've never thought about it before!!

So, if I can figure out (from the collar) the weight of empty versus full I'll be able to calculate a % full/empty - or, if I can't figure out the weights from the collar, I can use the link that Russell posted to get at least a rough estimate.

You can get BP Gaslight from Focus and you'll get the discount as well when they do their 15% off days/vouchers. The last 10kg one that I changed cost me £22 early last year, dunno what it costs at the moment coz 10kg lasts an awfully long time (we spent over 5 months in our van last year - four of them living in it and didn't manage to use up 10kg, we've still got 3kg left). We don't usually use it for heating or hot water but most of the cooking is done with gas on the hob or in the oven.

You can get BP Gaslight from Focus and you'll get the discount as well when they do their 15% off days/vouchers. The last 10kg one that I changed cost me £22 early last year, dunno what it costs at the moment coz 10kg lasts an awfully long time (we spent over 5 months in our van last year - four of them living in it and didn't manage to use up 10kg, we've still got 3kg left). We don't usually use it for heating or hot water but most of the cooking is done with gas on the hob or in the oven.